JP3306684B2 - Antenna pointing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna pointing device for pointing an antenna suitable for use in maritime satellite communication or the like toward a satellite.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional antenna pointing device. This antenna pointing device is basically called an azimuth-elevation system, and includes a base 3, an azimuth gimbal 40 mounted on the base 3, and a mounting bracket mounted on a U-shaped member at the upper end of the azimuth gimbal 40. 41 and the antenna 14 attached to the mounting bracket 41.

[0003] The base 3 may have a bridge portion 3-1.
The bridge portion 3-1 has a cylindrical portion 11 protruding upward.
Are mounted, and a pair of bearings 21-1 and 21-2 are mounted inside the cylindrical portion 11. An azimuth axis 20 is fitted to inner rings of the bearings 21-1 and 21-2, and an azimuth gimbal 40 is mounted on an upper end of the azimuth axis 20 via an arm 13.

[0004] Thus, the azimuth axis 20 is
With support by -2, azimuth gimbal 40 can rotate about an axis through azimuth axis 20. The azimuth gimbal 40 has a lower support shaft portion 40-1 and an upper U-shaped portion 40-2, and the center axis of the support shaft portion 40-1, that is, the azimuth axis ZZ is, as shown in FIG. Are deviated from the axis passing through. The support shaft 40-1 may be configured to be aligned with an axis passing through the azimuth axis 20.

[0005] A smaller U-shaped mounting bracket 41 is disposed on the U-shaped portion 40-2 of the azimuth gimbal 40, and the mounting bracket 41 has two legs 41-.
1 and 41-2 have elevation axes 30-1 and 30-2, respectively. Appropriate bearings are mounted on each of the two legs of the U-shaped portion 40-2 of the azimuth gimbal 40, and the elevation shafts 30-1 and 30-2 are rotatably supported by the bearings.

The central axes of the elevation axes 30-1 and 30-2 constitute an elevation axis YY, and thus the mounting bracket 41 is provided between the two legs of the U-shaped part 40-2 of the azimuth gimbal 40. Are supported rotatably about the elevation axis YY. The elevation axis YY is arranged at right angles to the azimuth axis ZZ.

The azimuth axis ZZ is perpendicular to the mounting surface of the antenna pointing device, for example, the hull plane, so that the elevation axis YY is always arranged parallel to the hull plane.

The leg 41 of the U-shaped mounting bracket 41
An antenna 14 is mounted on each of the antennas 1 and 41-2.
It can rotate around Y. The antenna 14 has a central axis XX, such a central axis being an elevation axis Y-.
Perpendicular to Y.

The mounting bracket 41 includes an elevation gyro 44.
The azimuth gyro 45 is attached, the rotation angle velocity of the antenna 14 rotating around the elevation axis YY is detected by the elevation gyro 44, and both the elevation axis YY and the center axis XX of the antenna 14 are detected by the azimuth gyro 45. The rotational angular velocity of the antenna 14 about an axis orthogonal to the angle is detected. The elevation gyro 44 and the azimuth gyro 45 may be, for example, an integrating gyro such as a mechanical gyro or an optical gyro, or an angular velocity detecting gyro such as a vibration gyro, a rate gyro, or an optical fiber gyro.

The mounting bracket 41 is further provided with a first accelerometer 46, a second accelerometer 47, and a third accelerometer 48. The first accelerometer 46 detects the inclination angle of the center axis XX of the antenna 14 around the elevation axis YY, and the second accelerometer 47 detects the inclination angle x of the elevation axis YY with respect to the horizontal plane. You.

If the second accelerometer 47 is mounted on the mounting bracket 41 so that its input axis is parallel to the elevation axis YY, its output is proportional to sinx. Note that the second accelerometer 47 may be mounted on the azimuth gimbal 40 such that its input axis is parallel to the elevation axis YY.

The third accelerometer 48 is the first accelerometer 46
And the second accelerometer 47 are mounted so as to be orthogonal to both, ie, have an input axis orthogonal to both the input axis of the first accelerometer 46 and the input axis of the second accelerometer 47. It is attached. Thus, the third accelerometer 48 has a central axis XX and an elevation axis Y-
The inclination angle of the axis perpendicular to both Y with respect to the horizontal plane is detected.

An elevation gear 32 is mounted on one leg of the mounting bracket 41 coaxially with the elevation axis YY. A pinion 35 is meshed with the elevation gear 32, and the pinion 35 is mounted on one leg of the U-shaped part 40-2 of the azimuth gimbal 40.
3 is attached to the rotating shaft.

An elevation transmitter 34 is mounted on one leg of the U-shaped part 40-2 of the azimuth gimbal 40. The elevation transmitter 34 allows the elevation axis YY of the antenna 14 to be mounted.
The surrounding rotation angle θ is detected, and a signal indicating the detection is output.

On the other hand, an azimuth gear 2 is provided at the lower end of the azimuth axis 20.
2 is mounted, and an azimuth servomotor 23 and an azimuth transmitter 24 are mounted on the bridge section 3-1 of the base 3.
A pinion (not shown) attached to the rotation axis of the azimuth servomotor 23 and the azimuth transmitter 24 is configured to mesh with the azimuth gear 22.

As shown, an elevation control loop and an azimuth control loop are provided to control the antenna pointing device. The center axis X-X of the antenna 14 is a horizontal plane and contact angle of elevation theta _A of the antenna, the central axis X-X of the antenna 14 is the azimuth angle phi _A of the antenna meridian N and the angle in the horizontal plane.

The elevation control loop is configured to rotate the antenna 14 about the elevation axis Y-Y so that the elevation angle θ _A of the antenna coincides with the satellite altitude angle θ _S. Including. In the first loop, the output of the elevation gyro 44 is fed back to the elevation servomotor 33 via the integrator 54 and the amplifier 55. As a result, the antenna 14 with respect to the inertial space
Angular velocity about the elevation axis Y-Y is always kept at zero.

In the second loop, the first accelerometer 4
6. The output signal of the three-axis orthogonal accelerometer including the second accelerometer 47 and the third accelerometer 48 is supplied to the antenna elevation angle calculator 81. The antenna elevation angle calculator 81 receives the output signals g ₁ , g ₂ , and g ₃ of the _three accelerometers 46, 47, and 48, and calculates the elevation angle θ _A of the antenna 14, that is, the center axis XX of the antenna 14 with respect to the horizontal plane. calculating a tilt angle theta _a. Such an operation is executed based on the following equation (1).

[0019]

Tan θ _A = −g ₁ / (g ₂ sin ε + g ₃ cos ε) where tan ε = g ₂ / g ₃ ,

As is evident from equation (1), such an operation involves performing an arc tangent operation from the tangent of the elevation angle θ _A of the antenna 14, thereby obtaining the value of the elevation angle θ _A of the antenna 14 and its quadrant. . The function and configuration of the antenna elevation angle calculation unit 81 are described in detail in Japanese Patent Application No. 4-3487 filed by the same applicant as the present applicant.
See No. 45.

The signal indicating the elevation angle θ _A of the antenna 14 output from the antenna elevation angle calculation unit 81 is reduced by, for example, a signal indicating the manually set satellite altitude angle θ _S , and further passes through the attenuator 56. Then, it is input to the integrator 54 and the amplifier 55. This loop has an appropriate time constant for matching the elevation angle θ _A of the antenna 14 to the satellite altitude angle θ _S. Incidentally, the attenuator 56 may be provided with an integral characteristic in order to compensate for drift fluctuation of the elevation gyro 44.

The azimuth gimbal 4 as azimuth control loop azimuth phi _A of the antenna 14 matches the satellite azimuth angle phi _S
It is configured to control the azimuth of zero and has third and fourth loops as shown. In the third loop, the output signal of the bearing gyro 45 is
And an amplifier 59 feeds back to the azimuth servomotor 23 so that the antenna 14 can rotate the hull about an axis perpendicular to both the central axis XX and the elevation axis YY of the antenna 14, Can be stabilized.

In the fourth loop, a rotation angle signal indicating the rotation angle (rotation angle of the antenna) φ of the azimuth gimbal 40 is output from the azimuth transmitter 24, and the rotation angle signal is supplied to the adder 61. . In the adder 61, the rotation angle φ, the heading azimuth angle φ _C supplied from, for example, a magnetic compass or a gyro compass, and the inclination correction value Δφ _A supplied from the inclination correction calculation unit 93 are added, and the sum thereof is used as a satellite. azimuth angle phi _S is subtracted. The output signal of the adder 61 is further input to the integrator 58 via the attenuator 60. Antenna rotation angle φ, bow azimuth φ _C and tilt correction value Δφ _A
When the sum is equal to the satellite azimuth angle phi _S between the antenna 1
The direction 4 is stationary.

The inclination correction calculating section 93 includes the elevation angle transmitter 3
4 indicates a signal indicating the rotation angle θ of the antenna 14 around the elevation axis YY and the sine value sinx of the inclination angle x of the elevation axis YY with respect to the horizontal plane output from the second accelerometer 47. And the central axis XX and the elevation axis YY of the antenna output from the third accelerometer 48.
Enter a signal indicating the sine value sin [theta _P inclination angle theta _P with respect to the horizontal plane of the axis perpendicular to both of, it calculates a tilt correction value [Delta] [phi _A.

The inclination correction value Δφ _A is obtained by the following equation (2).

Tan Δφ _A = sin θ · sinx / sin θ _P

For details of the configuration and operation of the tilt correction calculation section 93, refer to Japanese Patent Application No. 5-2581 filed by the same applicant as the present applicant.

[0027] The azimuth control loop, having an appropriate time constant to match the azimuth angle phi _A of the antenna 14 to the satellite azimuth angle phi _S. Incidentally, the attenuator 60 may be provided with an integral characteristic in order to compensate for drift fluctuation of the azimuth gyro 45. That is, the outputs of the attenuators 56 and 60 correspond to the outputs of the integrating gyro torquer.

Thus, the antenna 14 is configured such that the central axis XX is directed toward the satellite by the elevation angle control loop and the azimuth angle control loop.

[0029]

However, in the conventional antenna pointing device, when the navigation body, such as the hull, makes a turning motion, the first, second, and third accelerometers 46, 47, and 48 are used.
Detects not only the static tilting motion of the mounting surface of the antenna pointing device, but also the turning acceleration of the hull.

When the hull accelerates or decelerates while the hull is moving straight, the first, second and third accelerometers 46, 4
Reference numerals 7 and 48 detect the linear acceleration.

Therefore, in the conventional antenna pointing device, an error occurs in the control signal in the control loop including the accelerometers 46, 47, and 48, and the center axis XX of the antenna 14 is shifted from the satellite direction to which the antenna 14 should originally be directed. There was a disadvantage of bias.

In view of the above, the present invention provides an antenna that can always point the antenna 14 in a good direction to the satellite even when the navigating body accelerates or decelerates in a turning motion or a rectilinear motion during navigation. It is an object to provide a pointing device.

[0033]

According to the present invention, a support member 41 having a central axis XX, for example, as shown in FIG.
, An azimuth gimbal 40 that rotatably supports the antenna 14 and the support member 41 around an elevation axis YY orthogonal to the central axis XX, and an azimuth gimbal 40 that is positioned on the elevation axis YY. A base 3 rotatably supporting around an orthogonal azimuth axis Z-Z, a first gyro 44 having an input axis parallel to the elevation axis Y-Y and fixed to the support member 41, and a center axis X- A second axis fixed to the support member 41 and having an input axis orthogonal to both the X axis and the elevation axis YY.
A gyro 45, a first accelerometer 46 that outputs a signal indicating an inclination angle of the central axis XX with respect to a horizontal plane,
A second accelerometer 47 for outputting a signal indicating the inclination angle of the elevation axis YY with respect to the horizontal plane, and a third accelerometer 47 having an input axis orthogonal to both the central axis XX and the elevation axis YY of the antenna. An accelerometer 48, an azimuth transmitter 24 for outputting a signal indicating a rotation angle of the azimuth gimbal 40 around the azimuth axis ZZ, and an elevation axis YY to the azimuth gimbal 40
An elevation transmitter 34 for outputting a signal indicating the rotation angle θ of the surrounding antenna 14, an output signal of the second accelerometer 47, an output signal of the third accelerometer 48, and an output signal of the elevation transmitter 34. an inclined correction calculation unit 93 for calculating the inclination correction value △ [Phi _a type, the antenna elevation angle calculating unit center axis X-X of the antenna calculates the antenna elevation angle theta _a formed between the horizontal plane,
And a signal obtained by subtracting a value corresponding to the altitude angle of the satellite from the output signals of the accelerometers 46, 47 and 48 to the first gyro 4
4 feeds back to the substantial ToruCa and the direction transmitter 2
4, the signal corresponding to the heading azimuth and the satellite azimuth, and the tilt correction value △ Φ output from the tilt correction calculation unit 93.
_A signal indicating _A is calculated by a first adder 61, and the output signal is fed back to a substantial torquer of a second gyro 45 so that the central axis XX of the antenna is directed to the satellite. in antenna pointing devices that are more and θ rotation angle of the inclined correction calculating unit 93 supplied tilted correction value from △ [Phi _a satellite altitude angle θs and elevation oscillator 34 supplied elevation axis Y-Y around the antenna A shaking angle calculator 94 for calculating a shaking angle of the mounting surface of the antenna pointing device.
And the swing angles η and η supplied from the swing angle calculation unit 94.
The first and second angles based on the vehicle traveling speed V, the inclination correction value △ Φ _A supplied from the inclination correction calculation unit 93, and the rotation angle θ of the antenna about the elevation axis YY supplied from the elevation transmitter 34. And a turning acceleration calculating unit 104 for calculating turning accelerations △ g _OV , △ g _XV , △ g _PV acting on the third accelerometers 46, 47, 48, and turning to the output signals of the accelerometers 46, 47, 48. Second adding the output signal of the acceleration calculating unit 104
And adder 105, 106, 107 and is provided, the second pressure
In the calculators 105, 106, and 107, the accelerometer 46,
The output signals of 47 and 48 are the outputs of the turning acceleration calculation unit 104.
The corrected acceleration is generated by the signal and corrected.
Velocity is tilt correction operation unit 93 and antenna elevation angle operation unit 8
1 is provided .

According to the present invention, in the antenna pointing device, the shaking angle calculating section 94 calculates the shaking angles η and の of the mounting surface of the antenna pointing device by the following equation. η = tan ^-1 (sin Δφ _A / tan θ) θ _S -ξ = tan ^-1 (tan Δφ _A / sin η) where η, 動: swing angle of mounting surface Δφ _A : tilt correction value θ: output signal of elevation angle transmitter θ _S : Satellite altitude angle

According to the present invention, an antenna pointing device
Therefore, the turning acceleration calculation unit 104 calculates the first and second
And the pivoting force acting on the third accelerometers 46, 47, 48
Speed Δg_OV, Δg_XV, Δg_PVIs calculated. Δg_OV= −cos θ ｛− (A_Xsinη sinξ + A_Y
cos η) sin Δφ _A+ A_XcosξcosΔφ_A｝
−sin θ (−A_Xcosη sinｓ + A_Ysinη) Δg_XV= (A_Xsinη sinξ + A_Ycosη) co
sΔφ_A+ A_XcosξsinΔφ_A Δg_PV= −sin θ ｛− (A_Xsinη sinξ + A_Y
cos η) sin Δφ _A+ A_XcosξcosΔφ_A｝
+ Cos θ (-A_Xcosη sinｓ + A_Ysinη) where A_X= − ｛D (V sinφ_C) / Dt｝ · sinφ_S−
｛D (Vcosφ_C) / Dt｝ · cosφ_S A_Y= − ｛D (V sinφ_C) / Dt｝ · cosφ_S+
｛D (Vcosφ_C) / Dt｝ · sinφ_S φ_S： Satellite azimuth φ_C: Heading azimuth

[0036]

According to the present invention, the sway angle calculating section 94 obtains the sway angles η and に よ っ て by the equation (4), and the turning acceleration calculating section 104 calculates the sway angle V and the sway angle η, の from the According to the equations, the turning accelerations Δg _OV , Δg _XV , Δg _PV
Is obtained and the output values of the first, second and third accelerometers 46, 47, 48 are corrected by the turning accelerations Δg _OV , Δg _XV , Δg _PV in the adders 105, 106, 107. Calculation part 81 and inclination correction calculation part 9
3 is supplied with an acceleration based on the actual inclination of the navigation body in which the effects of the turning acceleration of the navigation body and the acceleration and deceleration of the linear motion of the navigation body are eliminated. Therefore, even if the navigation body makes a turning movement or the navigation body accelerates and decelerates, the center axis XX of the antenna 14 can be accurately directed toward the satellite without being affected by such movement.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2, the same reference numerals are given to the corresponding portions in FIG. 3, and the detailed description thereof will be omitted.

FIG. 1 shows an example of an antenna pointing device according to the present invention. The antenna pointing device includes a base 3 and the base 3.
And a mounting bracket 41 mounted on the U-shaped member at the upper end of the azimuth gimbal 40, and the antenna 14 mounted on the mounting bracket 41.

The antenna 14 has a central axis XX, and an assembly consisting of the antenna 14 and a mounting bracket 41 mounted on the antenna 14 is an elevation axis YY orthogonal to the central axis XX. It is rotatably supported around. The azimuth gimbal 40 is supported by the base 3 so as to be rotatable around an azimuth axis ZZ orthogonal to the elevation axis YY.
In this manner, a support mechanism rotatable about two axes is formed, and the support mechanism is controlled so that the central axis XX of the antenna 14 is directed to the satellite.

The mounting bracket 41 includes an elevation gyro 44
A gyro 45, a first accelerometer 46, a second accelerometer 47, and a third accelerometer 48 are mounted.

The elevation gyro 44 makes the elevation axis YY
The rotational angular velocity of the antenna 14 rotating around is detected,
The azimuth gyro 45 detects the rotational angular velocity of the antenna 14 about an axis orthogonal to both the elevation axis YY and the central axis XX of the antenna 14, and a first accelerometer 46.
The central axis XX of the antenna 14 with respect to the horizontal plane
The second accelerometer 47 detects the inclination angle of the elevation axis YY with respect to the horizontal plane.

The third accelerometer 48 is the first accelerometer 46
And an input axis perpendicular to both the input axis of the second accelerometer 47 and the input axis of the second accelerometer 47. Therefore, the third accelerometer 48 is connected to the central axis X-
An inclination angle of an axis orthogonal to both the X and the elevation axis Y-Y with respect to a horizontal plane is detected.

The elevation gyro 44 and the azimuth gyro 45 may be, for example, angular velocity detecting gyros such as a vibration gyro and a rate gyro.

The antenna pointing device of this embodiment has an elevation control loop and an azimuth control loop as in the conventional example of FIG. Elevation control loop of this embodiment is the elevation axis of the antenna 14 as the elevation angle theta _A of the antenna is matched to the satellite altitude theta _S Y
It is configured to rotate around −Y and may be the same as a conventional elevation control loop.

The azimuth control loop is the azimuth φ _{A of the} antenna.
There is configured to rotate the antenna 14 to match the azimuth angle phi _S satellites azimuthal axis Z-Z around, as compared with the conventional azimuth control loop, newly upset angle calculating section 94 and turning The difference is that an acceleration calculation unit 104 is provided. That is, in the fourth loop of the related art, in addition to the tilt correction calculation unit 93, a swing angle calculation unit 94 and a turning acceleration calculation unit 104 are newly provided.
Adders 105, 106, 10 for inputting the output signal
7 are provided.

The oscillating angle calculator 94 calculates the signal indicating the tilt correction value Δφ _A output from the tilt correction calculator 93 and the rotation angle θ of the antenna 14 about the elevation axis Y-Y output from the elevation transmitter 34. A command signal and a signal indicating the satellite altitude angle θ _S are input, and the swing angles η and の of the mounting surface of the hull on which the antenna pointing device is mounted are calculated.

The turning acceleration calculation unit 104 includes a swing angle calculation unit 9
4, a signal indicating the tilt angle η, ξ, a signal indicating the tilt correction value Δφ _A, and a signal indicating the rotation angle θ of the antenna 14 about the elevation axis YY output from the elevation transmitter 34. And the traveling speed V of the hull are input, and the turning accelerations Δg _OV , Δg _XV , and Δg _PV applied to the first, second, and third accelerometers 46, 47, and 48 are calculated. Such turning accelerations Δg _OV , Δg _XV , and Δg _PV are respectively added to the adder 105,
106 and 107. The traveling speed V of the hull may be obtained from, for example, GPS.

The adders 105, 106 and 107 add the output signals of the corresponding accelerometers 46, 47 and 48 and the output signals of the turning acceleration calculator 104, and add the corrected acceleration signal generated thereby to the antenna. It is supplied to the elevation calculation unit 81 and the inclination correction calculation unit 93.

With reference to FIG. 2, the functions and operations of the swing angle calculating section 94 and the turning acceleration calculating section 104 of this embodiment will be described. FIG. 2 shows a unit spherical surface having a radius of 1, and the unit spherical surface and the central axis XX (line segment OX in FIG. 2) and the elevation axis YY (line segments OY, OY in FIG. 2) of the antenna 14 are considered. '), Azimuth axis Z
-Z (line segments OZ, OZ 'in FIG. 2) and antenna 14
FIG. 3 is a diagram showing a relationship between an axis perpendicular to both a central axis XX and an elevation axis YY (line segments OP and OP ′ in FIG. 2). The azimuth axis ZZ is always perpendicular to the hull plane (the mounting surface of the antenna pointing device).

The hull rotates by the sway angle ξ and then the sway angle η
Suppose only rotated. That is, consider a case where the hull rotates by a rotation angle (oscillation angle) 周 り about a first rotation axis and further by a rotation angle (oscillation angle) η about a second rotation axis. Due to the rotational movement of the hull, for example, as shown in the figure, the hull surface is elevated with respect to a horizontal plane by an axis of elevation YY (O
Y) It rotates around the angle of rotation ξ, and furthermore, the line O of the hull
It is assumed that the rotation around E is made by the rotation angle η. At this time,
The elevation axis YY is parallel to the first rotation axis, and the hull's tail line OE is parallel to the second rotation axis.

By the motion of the hull surface, the azimuth axis Z
−Z moves from line OZ to line OZ ′, and elevation axis YY moves from line OY to line OD. Note that 尚 XOD = 90 °. The central axis XX of the antenna 14 also moves, but the central axis XX of the antenna 14 is controlled by the control loop so as to point in the satellite direction. That is, the antenna 14
Move to a position deviated from the line OX and move again to the line OX.

[0052] By such a control, the elevation axis Y-Y moves 'by the rotation angle [Delta] [phi _A from rotating line OD line OY around' the azimuthal axis OZ. Note that ∠XOY '= 90 °.
Also, the center axis XX and the elevation axis YY of the antenna 14 are shown.
Move to the line OP '. Eventually, the line OY has moved to the line OY 'via the line OD, and ∠POP' = ∠Y'OY and arc PP '= arc Y'
Y.

The line OX, the line OY, and the line OP are lines having a length of 1 orthogonal to each other, and the triangle XYP is an equilateral spherical triangle having one side of π / 2. The line OX, the line OY ′, and the line OP ′ are also lines having a length of 1 orthogonal to each other, and the triangle XY′P ′ is an equilateral spherical triangle having one side of π / 2. Points X, P and P 'are connected by straight lines on the unit spherical surface. The arc XP is orthogonal to the horizontal plane at the point A, and is orthogonal to the plane OY'P 'at the point P. The arc XP 'is orthogonal to the hull plane (mounting plane) at the point C, and is orthogonal to the plane OY'P' at the point P '. Let A 'be a leg of a perpendicular line lowered from the point P' to the horizontal plane, and B 'be a leg of a perpendicular line lowered from the point Y' to the horizontal plane.

Here, ∠XOA = θ ₀ = arc XA, ∠PO
A = θ _P0 = arc PA, ΔBOD = η = arc BD, ΔXOC =
θ = arc XC, ∠P'OA '= θ _P = arc P'A', ∠Y '
OB ′ = x = arc Y′B ′.

The first accelerometer 46 is mounted along line OX, the second accelerometer 47 is mounted along line OY,
The third accelerometer 48 is mounted along the line OP.
When the hull plane is the same as the horizontal plane, the elevation angle transmitter 34 outputs the inclination angle ∠XOA = θ ₀ of the center axis XX of the antenna 14 with respect to the hull plane, and the first accelerometer 46 gives sin∠XOA = sin θ. ₀ is detected, sin∠YOB = sin0 = 0 is detected by the second accelerometer 47, and sin 計 POA is detected by the third accelerometer 48.
= Sin θ _P0 is detected.

As described above, when the hull surface rotates about the elevation axis YY (OY) with respect to the horizontal plane by the rotation angle ξ and further rotates about the hull end line OE by the rotation angle η,
The elevation angle transmitter 34 outputs the inclination angle ∠XOC = θ of the central axis XX of the antenna 14 with respect to the hull plane,
Sin∠XOA = sin θ ₀ is detected by the accelerometer 46, and sin∠Y′O is detected by the second accelerometer 47.
B ′ = sinx is detected, and the third accelerometer 48 detects sin∠P′OA ′ = sin θ _P. First
Detected by the accelerometer 46 of sin @ XOA =
The reason why sin θ ₀ does not change is that the satellite altitude angle θ _S (= θ
_A. ) Has nothing to do with the motion of the hull.

Next, the relationship between the tilt correction value Δφ _A and the oscillation angle η, ξ is determined. Tilt correction value Δφ _A = arc EC = arc D
Y '. Note that the inclination correction value Δφ _A is, as described above,
It is obtained by the equation of Equation 1. By applying the spherical trigonometric theorem, the following equation 3 is obtained.

[0058]

## EQU3 ## sin Δφ _A = tanη · tan θ cosη = sin θ / sin (θ _{S − S} ) cos Δφ _A · cos θ = cos (θ _S −ξ)

Here, η and ξ are the swing angles, Δφ _A is the inclination correction value, and θ is the rotation angle of the antenna about the elevation axis YY with respect to the azimuth gimbal 40. When the oscillation angles η and ξ are obtained from the equation (3), the following equation (4) is obtained.

[0060]

Η = tan ⁻¹ (sin Δφ _A / tan θ) θ _S −ξ = tan ⁻¹ (tan Δφ _A / sin η)

According to this embodiment, the operation of the equation (4) is executed in the oscillation angle computing section 94, whereby the oscillation angles η and ξ are obtained. The signals for instructing the swing angles η and ξ are supplied from the swing angle calculator 94 to the turning acceleration calculator 104.

The tilt correction value Δφ _A can be obtained as an output value of the tilt correction calculation unit 93, but is preferably obtained as follows. The fourth loop is configured to control the azimuth of the azimuth gimbal 40 so that the output of the adder 61 becomes zero. Therefore, when the output of the adder 61 is zero, the following equation (5) is obtained. Holds.

[0063]

[Equation 5] Δφ _A = φ _S -φ _C -φ

Here, φ _S is the satellite azimuth, φ _C is the heading azimuth, and φ is the rotation angle of the azimuth gimbal 40 output by the azimuth transmitter 24. Each term on the right side of the equation (5) can be determined as a value that is not directly affected by the sway acceleration or a value that is less affected by the sway acceleration.
Therefore, the inclination correction value Δφ _A may be obtained by using the expression of Expression 5 instead of using the output value of the inclination correction operation unit 93.

As described above, the turning acceleration calculator 104 calculates the swing angle η, ξ obtained from the swing angle calculator 94 and the tilt correction value Δ obtained from the tilt correction calculator 93 or the equation (5).
More and phi _A and the rotation angle θ and the moving speed V of the ship elevation oscillator elevation axis Y-Y around obtained from 34 antenna 14, first, second and third accelerometers 46, 47, 48 The turning accelerations Δg _OV , Δg _XV , and Δg _PV applied to each are calculated. This arithmetic expression is shown in Equation 6.

[0066]

## EQU6 ## Δg_OV= −cos θ ｛− (A_Xsinη sin
ξ + A_Ycos η) sin Δφ _A+ A_Xcos @ cos
Δφ_A｝ -Sin θ (-A_Xcosη sinｓ + A_Ys
inη) Δg_XV= (A_Xsinη sinξ + A_Ycosη) co
sΔφ_A+ A_XcosξsinΔφ_A Δg_PV= −sin θ ｛− (A_Xsinη sinξ + A_Y
cos η) sin Δφ _A+ A_XcosξcosΔφ_A｝
+ Cos θ (-A_Xcosη sinｓ + A_Ysinη)

Where A _X = − {d (V sin φ _C ) / dt} · sin φ _S −
_{{D (Vcosφ C) / dt} } · cosφ S A Y = - {d (Vsinφ C) / dt} · cosφ S +
{D (Vcosφ _C ) / dt} · sin φ _S φ _S : satellite azimuth φ _C : bow azimuth

A signal indicating the first turning acceleration Δg _OV is supplied to the adder 105, a signal indicating the second turning acceleration Δg _XV is supplied to the adder 106, and indicating the third turning acceleration Δg _PV . The supplied signal is supplied to the adder 107.

In each of the adders 105, 106 and 107, the accelerations supplied from the corresponding accelerometers 46, 47 and 48 and the corresponding turning accelerations Δg _OV , Δg _XV and Δg _PV are added and corrected. Each acceleration is generated.
Such a corrected acceleration is corrected to a value that does not include a component of the turning acceleration applied to each of the accelerometers 46, 47, and 48 and a component of the acceleration / deceleration of the traveling speed. Thus, the accelerometers 46, 4 including the component of the turning acceleration and the component of the acceleration / deceleration of the traveling speed are provided to the antenna elevation angle calculation unit 81 and the inclination correction calculation unit 93.
Instead of the acceleration values of 7 and 48, an acceleration value that does not include the component of the turning acceleration and the acceleration / deceleration component of the traveling speed is supplied.

Although not shown in FIG. 1, each adder 10
A low-pass filter having a sufficiently small time constant as compared with the constraint time constants of the second and fourth loops may be provided on the output side of 5, 106 and 107.

According to this embodiment, the influence of the turning acceleration acting on the first, second and third accelerometers 46, 47 and 48 is eliminated by providing the swing angle calculating section 94 and the turning acceleration calculating section 104. Antenna elevation angle calculation unit 8
The acceleration based on the actual inclination of the hull is supplied to 1 and the inclination correction calculation unit 93. Therefore, even if the hull turns and the traveling speed is accelerated or decelerated, the antenna 1 is highly accurate.
4 can be directed toward the satellite.

Although the embodiments of the present invention have been described in detail, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments and can adopt various other configurations without departing from the gist of the present invention. It will be easily understood.

[0073]

According to the present invention, the navigating body performs the turning motion and the increasing / decreasing motion of the operating speed, whereby the first, second and third accelerometers 46, 47, 48 provide the turning acceleration and the straight acceleration. Even if it is added, the sway angle η, ξ is obtained by the sway angle calculation section 94 by the equation (4), and the turning acceleration Δ
g _OV , Δg _XV , Δg _PV are obtained, and the adders 105, 10
6, 107, the first, second and third accelerometers 4
The output values of 6, 47, 48 are the turning acceleration components Δg _OV , Δg
_XV, since is corrected by Delta] g _PV, the antenna elevation angle calculating unit 81 and the inclined correction calculation unit 93 has the advantage that the acceleration based on the actual inclination of the sail body is supplied.

According to the present invention, in the elevation angle control loop, the acceleration based on the actual inclination of the navigation body is supplied to the antenna elevation angle calculation unit 81, so that the effects of the turning acceleration and the straight acceleration of the navigation body are eliminated. Therefore, there is an advantage that the antenna 14 can be directed to the satellite with high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an antenna pointing device according to the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of the antenna pointing device on a unit spherical surface.

FIG. 3 is a diagram showing an example of a conventional antenna pointing device.

[Explanation of symbols]

 3 Base 3-1 Bridge part 11 Cylindrical part 13 Arm 14 Antenna 20 Azimuth axis 21-1, 21-2 Bearing 22 Azimuth gear 23 Azimuth servomotor 24 Azimuth transmitter 30-1, 30-2 Elevation axis 32 Elevation gear 33 Elevation servomotor 34 Elevation transmitter 35 Pinion 40 Azimuth gimbal 40-1 Support shaft 40-2 U-shaped part 41 Mounting bracket 41-1, 41-2 Leg 44 Elevation gyro 45 Azimuth gyro 46 First accelerometer 47 2 accelerometer 48 third accelerometer 54 integrator 55 amplifier 56 attenuator 58 integrator 59 amplifier 60 attenuator 61 adder 81 antenna elevation angle calculation unit 93 tilt correction calculation unit 94 shaking angle calculation unit 104 turning angle speed calculation unit 105 , 106, 107 Adders XX Antenna center axis YY Elevation axis ZZ Azimuth axis

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-14504 (JP, A) JP-A-59-87513 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 3/00-3/46

Claims (3)

(57) [Claims] An antenna having a central axis supported by a support member, an azimuth gimbal rotatably supporting the antenna and the support member about an elevation axis orthogonal to the central axis, and A base rotatably supported around an azimuth axis orthogonal to the elevation axis, a first gyro having an input axis parallel to the elevation axis and fixed to the support member, and both the center axis and the elevation axis A second gyro having an input axis perpendicular to the axis, a first gyro fixed to the support member, a first accelerometer for outputting a signal indicating an inclination angle of the central axis with respect to a horizontal plane, and an inclination of the elevation axis with respect to a horizontal plane A second accelerometer for outputting a signal indicating an angle, a third accelerometer having an input axis orthogonal to both the central axis and the elevation axis of the antenna, and the azimuth axis of the azimuth gimbal An azimuth transmitter that outputs a signal that indicates a rotation angle around a line, an elevation transmitter that outputs a signal that indicates a rotation angle of the antenna around the elevation axis with respect to the azimuth gimbal, and a second accelerometer. An inclination correction operation unit that inputs an output signal, an output signal of the third accelerometer, and an output signal of the elevation angle transmitter to calculate an inclination correction value; and an antenna elevation angle in which the central axis of the antenna forms a horizontal plane. An antenna elevation angle calculating unit for calculating, and feeding back a signal obtained by subtracting a value corresponding to the altitude angle of the satellite from the output signal of the accelerometer to a substantial torquer of the first gyro, The first output signal, the signal corresponding to the heading azimuth and the satellite azimuth, and the signal indicating the tilt correction value △ Φ _A output from the tilt correction calculator are first
And an output signal fed back to the substantial torquer of the second gyro to direct the center axis of the antenna to the satellite. A tilt correction value, a satellite altitude angle supplied from the unit, a rotation angle of the antenna around the elevation axis supplied from the elevation transmitter, and a rotation angle calculation unit for calculating a rotation angle of the mounting surface of the antenna pointing device from the elevation correction axis; The oscillation angle and the navigation vehicle traveling speed supplied from the oscillation angle calculation unit, the inclination correction value supplied from the inclination correction operation unit, and the rotation angle of the antenna about the elevation angle axis supplied from the elevation transmitter. A turning acceleration calculator for calculating a turning acceleration acting on the first, second, and third accelerometers; and an output signal of the turning acceleration calculator for an output signal of the accelerometer. A second adder for adding the provided, the second pressure
In the calculator, the output signal of the accelerometer is
The corrected acceleration generated by the output signal of the
And the corrected acceleration is calculated by the inclination correction calculation unit and the
An antenna pointing device configured to be supplied to an antenna elevation angle calculation unit . 2. The antenna pointing device according to claim 1, wherein the swing angle calculation unit calculates a swing angle of a mounting surface of the antenna pointing device by the following equation. η = tan ^-1 (sin Δφ _A / tan θ) θ _S -ξ = tan ^-1 (tan Δφ _A / sin η) where η, 動: swing angle of mounting surface Δφ _A : tilt correction value θ: output signal of elevation angle transmitter θ _S : Satellite altitude angle 3. The antenna pointing device according to claim 1, wherein:
In the above, the turning acceleration calculating section calculates the turning acceleration by the following equation.
Turning acceleration Δg acting on the first, second and third accelerometers
_OV, Δg_XV, Δg_PVWhich is characterized by calculating
Directional device. Δg_OV= −cos θ ｛− (A_Xsinη sinξ + A_Y
cos η) sin Δφ _A+ A_XcosξcosΔφ_A｝
−sin θ (−A_Xcosη sinｓ + A_Ysinη) Δg_XV= (A_Xsinη sinξ + A_Ycosη) co
sΔφ_A+ A_XcosξsinΔφ_A Δg_PV= −sin θ ｛− (A_Xsinη sinξ + A_Y
cos η) sin Δφ _A+ A_XcosξcosΔφ_A｝
+ Cos θ (-A_Xcosη sinｓ + A_Ysinη) where A_X= − ｛D (V sinφ_C) / Dt｝ · sinφ_S−
｛D (Vcosφ_C) / Dt｝ · cosφ_S A_Y= − ｛D (V sinφ_C) / Dt｝ · cosφ_S+
｛D (Vcosφ_C) / Dt｝ · sinφ_S φ_S： Satellite azimuth φ_C: Heading azimuth